Device for removing screws



Oct. 25, 1955 F. E. HAMMER DEVICE FOR REMOVING SCREWS Filed April 19, 1954 INVENTOR. F1220 1E. HAMMER BY United States Patent DEVICE, FOR REMOVING SCREWS EredE- H mm rs 1870mm,-

Application April 19, 1954, 'SerialNo.'423,'890

. .Claims. (61.: 144-32) This invention relates to' a new, and improved device .forremoving screws. The ingen tion haspar'ticularapnecessary to apply considerableforce to loosen the screws when it is-necessary to remove them, ;Particularly when the screw 'is locatedpn the top surface of the -wing, it is difficult to apply enough force to the screwdriver to maintain the blade seated in the slot, for the reason that the mechanic .cannotapply J'hiS full'v weight tothe handle of the screwdriver and there is no purchase enabling him to apply other force to the blade. It will be understood that similar problems occur in other exposed positions and that the present invention finds application under such conditions.

The present invention employs suction means to be attached to the wing surface or other area where the screws are located and a means cooperating with the suction means employing a blade which fits into the screw slot. Inasmuch as the suction means maintains its position on the wing against a considerable force, much greater pressure may be applied to the screwdriver blade than is otherwise possible. The present invention affords means whereby the screwdriver blade is enabled to seat tightly into the bottom of the screw slot by reason of the fact that a latching means is employed to disengage the screwdriver blade from the means for driving the same, thereby enabling the blade to seat substantially vertically into the slot without turning movement.

More particularly the invention employs a yoke frame which is attached to the wing by means of suction cups and athreaded spindle threaded into the frame which carries a screwdriver bit at its lower end, there being a loose connection between the bit and the spindle to enable the blade of the bit to seat in the screw slot and a latching means to lock the blade and spindle for movement together when it is desired to loosen the screw.

Other objects of the present invention will become apparent upon reading the following specification and referring to the accompanying drawings in which similar characters of reference represent corresponding parts in each of the several views.

In the drawings:

Fig. 1 is a top plan of the device.

Fig. 2 is a vertical section taken substantially along the line 22 of Fig. 1.

Fig. 3 is a transverse section taken substantially along the line 3-3 of Fig. 1, but showing the device attached to a flat surface.

The present invention employs a substantially yokeshaped frame formed of bar steel bent in a shape which has a horizontal, central or top portion 11, substantially "non-circular shape 26 (e. g. square).

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vertically depending ,legs12 on each end of the.top portion andoutwardly extending, substantially horizontal feet 13 at the lower ends of the legs. A conventional rubber-suction cup 14 is attached at the bottom of each foot as by means of stud 16 threaded into foot13 or other suitable attaching means. Immediately above the suction cups on the top surface of each foot is a handle 17, likewise attached to the frame by stud16. By pushing' downwardly on the handles 17, the attendant can force the suction "cups 14 into secure engagement with the flat surface 18 in which the screw 19, having slot 20 which is to' be removed is located.

A tapped hole 21 is formed in the center section 11 of the frame and a substantially vertical, threaded spindle 22 passes through the hole-21. A handle 23 is provided for the upper end of the spindle. The lower end of the spindle is formedwith an axial bore 24 and the exterior of the bottom of the spindle is enlarged and formed in a Fitting into the bore 24 is a bit 27- having a screwdriver'blade 28 to accommodate slot 20 at its lower end; an external enlarged shoulder 29 above the bit; a non-circular'portion 31 of "fitting into the bore 24. A groove 33 is formed in the upper end of the'shank and a set screw 34 passing through the-wall-of-thespindle fits into the groove and enables the shank to turn relativeto the spindle but prevents .the shank-from falling out of the bore. vIt will thus be seen that the screwdriver bit 27 is held by the spindle 22, but may turn relative thereto, for a purpose which hereinafter appears.

Latch means are provided to lock the spindle and bit together. Such a latch means as illustrated herein employs a collar 36 which has a nonscircular hole 37 approximately the same size and shape as the non-circular shape of the lower end 26 of the spindle 22 and the portion 31 of the bit 27 immediately above enlarged shoulder 29. Shoulder 29 prevents the collar 36 from falling off the device. When the collar is raised to the dot-anddash position shown in Fig. 2, there is no impediment to rotative movement of the spindle 22 relative to the bit 27. However, when the collar 36 is lowered to the solid line position of Fig. 2, by reason of the non-circular shape of the hole 37 in the collar 36, end 26 of the spindle 22, and portion 31 of the bit 27, the spindle and bit are latched for turning movement together.

In use, the mechanic locates the device on the wing 18 so that the shank 22, which has been turned upwardly, is substantially immediately above the screw 19 to be removed. The handles 17 are then depressed which causes the suction cups 14 to secure the yoke to the wing surface. With the collar 36 pulled upwardly out of engagement with the enlarged portion 3-1 of the bit 27, spindle 22 is turned by handle 23 so that the bit 27 is depressed, the blade 28 fitting in the screw slot 20 until it is fully seated in the bottom of the slot. The fact that the bit 27 is rotatable relative to the spindle 22 permits the blade to be seated substantially vertically without any turning movement while the spindle is being turned. When the blade is fully seated in the screw slot, the collar 36 is dropped into position shown in full lines in Figs. 2 and 3 which insures that the spindle and bit will turn together. Thereupon, the handle 23 is given an unwinding movement which twists the blade 28 to loosen the screw 19 to be removed. Although it is desirable that the threads on the spindle and the threads on the screw be identical in order to withdraw the screw its whole length, nevertheless, if they are not identical, sufficient twisting force can be applied to the screw 19 to loosen it sufficient- 1y so that a conventional screwdriver may be employed to complete removal.

Although the foregoing invention has been described in some detail by way of illustration and example for purposes of clarity of understanding, it is understood that certain changes and modifications may be practiced within the spirit of the invention and scope of the appended claims.

What is claimed is:

1. A fastener removing tool comprising, a frame, means for detachably securing said frame to a surface containing a fastener to be removed with said frame fixed in position relative to said surface when thus secured, a fastener engaging tool head rotatable means cooperating with said frame for raising and lowering said head, and detachable latch means for latching said rotatable means and head for rotation together.

2. A fastener removing tool comprising, a frame, means for detachably securing said frame to a surface containing a fastener to be removed with said frame fixed in position relative to said surface when thus secured, a fastener engaging tool head, a spindle in threaded engagement with said frame, means for attaching said spindle and head for relative rotative movement, and detachable latch means for latching said spindle and head for rotative movement together.

3. A tool according to claim 2 in which juxtaposed portions of said spindle and head are formed non-circular and there is provided a collar having a non-circular hole similar in size and shape to the non-circular portions of said spindle and head, said collar being slidable from a position engaging both said spindle and head for rotation together to a position out of engagement with at least one of the non-circular portions of said spindle and head.

4. A fastener removing tool comprising a yoke-shaped frame, a suction cup carried on each bottom leg of said frame for securing said frame to a surface bearing a fastener to be removed with said frame being substantially rigid relative to said surface when said frame is secured thereto, a spindle in threaded engagement with said frame, and a fastener engaging tool head on the lower end of said spindle.

5. A fastener removing tool comprising a yoke-shaped frame, suction cups carried on the bottom legs of said frame for securing said frame to a surface bearing a fastener to be removed, a spindle in threaded engagement with said frame, a fastener engaging tool head on the lower end of said spindle, means securing said head to said spindle for rotation relative thereto, juxtaposed portions of said spindle and head being formed non-circular, and a collar having non-circular hole complementary to said juxtaposed portions and moveable between a position fitting over both said juxtaposed portions to lock said spindle and head for rotation together to a position out of engagement with at least one of said juxtaposed portions to permit relative rotative movement of said spindle and head.

References Cited in the file of this patent UNITED STATES PATENTS 2,621,688 Wales Dec. 16, 1952 2,632,486 Fetsko Mar. 24, 1953 2,679,270 Krause May 25, 1954 FOREIGN PATENTS 391,124 Great Britain Apr. 18, 1933 

